Laura Kresty, PhD, assistant professor in the Ohio State University Cancer Chemoprevention Program, Columbus, reported that 58% of 20 Barrett's esophagus patients who ate a freeze-dried preparation of black raspberries daily for 26 weeks had a significant decline in mean urinary levels of 8-isoprostane, an indicator of global oxidative stress and DNA damage (abstract B34).

"Many of these patients had suffered from gastroesophageal reflux for a decade," Dr. Kresty said at a press briefing. "Injury from acids results in generation of reactive oxygen species, which then cause damage. We tested this preparation in an attempt to decrease the ongoing oxidative stress in these patients."

The take-home message, she said: "We need to increase fruit and vegetable consumption, and patients can do something to modify some pathways that lead to cancer."

She recommended that the lyophilized black raspberry formulation be further studied in a randomized, placebo-controlled phase II trial.

An oral gel

Susan Mallery PhD, DDS, and her colleagues took a different approach. Her group tested a highly concentrated, bioadhesive black raspberry gel as a topical treatment for precancerous oral lesions (abstract B35). Dr. Mallery is a professor in the Department of Oral Maxillofacial Surgery and Pathology at Ohio State University's College of Dentistry.

"The major problem with patients who have these premalignant lesions is recurrent disease that appears postop despite clear surgical margins," Dr. Mallery said. "Black raspberries are full of anthocyanins, potent antioxidants that give the berries their rich, dark color, and our findings show that these compounds may have a role in silencing precancerous cells."